go/api
Carlos Amedee 83df0afc4e runtime/trace: add the flight recorder
This change adds the flight recorder to the trace package.
Flight recording is a technique in which trace data is kept
in a circular buffer and can be flushed upon request. The
implementation will be added in follow-up CLs.

The flight recorder has already been implemented inside of the
golang.org/x/exp/trace package. This copies the current implementation
and modifies it to work within the runtime/trace package.

The changes include:

This adds the ability for multiple consumers (both the execution
tracer and the flight recorder) to subscribe to tracing events. This
change allows us to add multiple consumers without making major
modifications to the runtime. Future optimizations are planned
for this functionality.

This removes the use of byte readers from the process that
parses and processes the trace batches.

This modifies the flight recorder to not parse out the trace
clock frequency, since that requires knowledge of the format that's
unfortunate to encode in yet another place. Right now, the trace clock
frequency is considered stable for the lifetime of the program, so just
grab it directly from the runtime.

This change adds an in-band end-of-generation signal to the internal
implementation of runtime.ReadTrace. The internal implementation is
exported via linkname to runtime/trace, so the flight recorder can
identify exactly when a generation has ended. This signal is also useful
for ensuring that subscribers to runtime trace data always see complete
generations, by starting or stopping data streaming only at generation
boundaries.

For #63185

Change-Id: I5c15345981a6bbe9764a3d623448237e983c64ec
Reviewed-on: https://go-review.googlesource.com/c/go/+/673116
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-05-21 18:39:54 -07:00
..
next runtime/trace: add the flight recorder 2025-05-21 18:39:54 -07:00
except.txt syscall: selectively update zerrors_* on openbsd/386, openbsd/arm and openbsd/amd64 2024-06-16 23:08:08 +00:00
go1.1.txt strconv: quote rune 007F as \x7f, not \u007f 2022-03-31 20:37:15 +00:00
go1.2.txt api: add go1.2.txt, use in tests 2013-10-18 13:36:59 +09:00
go1.3.txt api: add go1.3.txt 2014-06-02 11:45:00 +09:00
go1.4.txt [release-branch.go1.4] api: create go1.4.txt 2014-12-12 14:01:01 +11:00
go1.5.txt api: update go1.5.txt 2015-07-30 21:14:09 +00:00
go1.6.txt go/types: rename Importer2 to ImporterFrom 2016-01-13 23:40:13 +00:00
go1.7.txt unicode: upgrade to version 9.0.0 2016-06-28 15:08:11 +00:00
go1.8.txt Revert "cmd/go: note when some Go files were ignored on no-Go-files errors" 2016-12-21 05:25:57 +00:00
go1.9.txt cmd/api: set architecture sizes when type checking 2021-10-04 20:20:20 +00:00
go1.10.txt text/template: revert CL 66410 "add break, continue actions in ranges" 2018-02-06 05:00:01 +00:00
go1.11.txt crypto/tls: make ConnectionState.ExportKeyingMaterial a method 2018-08-22 03:48:56 +00:00
go1.12.txt api: add os.(*File).SyscallConn to go1.12.txt 2019-01-02 21:21:53 +00:00
go1.13.txt api/go1.13: add debug/elf.Symbol fields added in CL 184099 2019-08-08 18:44:16 +00:00
go1.14.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.15.txt go/printer: remove exported StdFormat flag 2020-07-17 02:15:01 +00:00
go1.16.txt cmd/api: track darwin arm64 port 2022-12-02 16:30:41 +00:00
go1.17.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.18.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.19.txt cmd/api: track deprecations 2022-12-02 16:29:41 +00:00
go1.20.txt cmd/api: add API checks for freebsd/riscv64 2023-02-17 21:23:32 +00:00
go1.21.txt go/ast: deprecate Object 2023-08-07 09:39:17 +00:00
go1.22.txt Revert "archive/tar: add FileInfoNames interface" 2024-01-24 20:54:27 +00:00
go1.23.txt crypto/tls: apply QUIC session event flag to QUICResumeSession events 2024-06-25 17:08:08 +00:00
go1.24.txt debug/elf: adjust version API per issue discussion 2024-12-17 13:28:29 -08:00
go1.txt encoding/xml: add, support Marshaler interface 2013-08-14 14:58:28 -04:00
README api/README: refer to doc/README.md 2024-01-31 19:22:50 +00:00

Files in this directory are data for Go's API checker ("go tool api", in src/cmd/api).

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"
giving the GitHub issue number of the proposal issue that accepted
the new API. This helps with our end-of-cycle audit of new APIs.
The same requirement applies to next/* (described below), which will
become a go1.XX.txt for XX >= 19.

The next/ directory contains the only files intended to be mutated.
Each file in that directory contains a list of features that may be added
to the next release of Go. The files in this directory only affect the
warning output from the go api tool. Each file should be named
nnnnn.txt, after the issue number for the accepted proposal.
(The #nnnnn suffix must also appear at the end of each line in the file;
that will be preserved when next/*.txt is concatenated into go1.XX.txt.)

When you add a file to the api/next directory, you must add at least one file
under doc/next. See doc/README.md for details.